Variability of the vertebral artery origin and transverse foramen entrance level — CT angiographic study

Abstract

Vertebral artery (VA), the main element of the posterior brain circulation, has many anatomical variations which generally were widely investigated. However, available data vary in wide ranges, reflecting very different sample sizes, lack of data about left-right or sex differences, and about possible ethnic, regionally specific or genetic differences. Certain new findings suggest possible involvement of some environmental factors in VA variations. Accurate anatomical data about VA variations in different regions of the world, including Balkans countries, are still lacking. Therefore we investigated morphological variability of VA origin and its entrance level into cervical transverse foramina in population of Republika Srpska (Bosnia and Herzegovina), including data about the sex and side. Anatomy of VA was investigated in 112 persons (224 arteries) of both sexes (58 males, 54 females; age 19 - 83 years), using 64-slice CT scanner. Origin of VA from subclavian artery (SCA) we found in 95.08% of arteries (52 males, 49 females). Only in one male (0.45 %) left VA and left SCA had an specific origin from aortic arch (AA), which we named as an "common area of origin". All other observed variations in origin were only of left VA, originating from AA in 4.47 % (5 males, 5 females). Left VA Most often (usual) entrance level into transverse foramen we found at C6 (87.5%), followed by C5 (8.93 %), C4 (3.12 %), and in one case at level C7 (0.45 %). Entry levels at C5 both, on right and on the left side, were 3 times more frequent in males than in females. Wide ranges of differences between the data we obtained on a sample in Republika Srpska (Bosnia and Herzegovina) and the data from many other studies require further and wider investigations.

An anatomical investigation of the proximal vertebral arteries (V1, V2) in a select South African population

“…The incidence in the current study (6.9%) is similar to previous cadaveric report from South African population (8.5%) (Doctoral dissertation, University of Cape Town). Our result is also comparable to recent reports that used similar imaging modalities (CTA) in an Egyptian population (7%) [ 1 ] but slightly higher than reports from Republika Srpska population (4.47%) [ 40 ] and Turkish population (3.6%) [ 2 ]. In the present study, the comparison of the incidence across the racial groups showed that variation in origin is highest in White (3.6%), followed by Indian (2.5%) and least in Black (0.7%) South African.…”

Neck movement during cervical transforaminal epidural injections and the position of the vertebral artery: an anatomical study

“…In addition to supplying the spinal cord, the vertebral arteries also feed the brainstem and posterior regions of the brain. Anatomical variations—including lateral loops, different origins, course variations through the craniocervical junction, and accessory vessels of the vertebral artery—have been previously reported in the literature with imaging techniques and anatomical dissections (7,8).…”

Sex and level differences in the diameters of extradural segment of vertebral artery: computed tomography angiographic study

“…Of these we selected 91 adult persons (182 VAs) of both sexes (47 males and 44 females) and of age between 33 and 75 years (Table 1) for the study of VA diameters. From the study were excluded the patients with abnormal morphology of VA, with unusual anatomical features (variations of origin described previously [26], kinking and coiling) or with previous or current cerebrovascular accidents, with injuries of cervical region, vertebrobasilar insufficiency, atherosclerotic changes of vessels (affecting more than 50% of VA diameter), with developmental abnormalities of cervical spine and with severe spondyloarthrosis. The patients were selected according to the described criteria, and only those of so selected patients who also gave informed consent (91 patients) were finally included in this study.…”